error: The function/method `takes_an_immutable_reference` doesn't need a mutable reference --> $DIR/mut_reference.rs:32:34 | 32 | takes_an_immutable_reference(&mut 42); | ^^^^^^^ | = note: `-D clippy::unnecessary-mut-passed` implied by `-D warnings` error: The function/method `as_ptr` doesn't need a mutable reference --> $DIR/mut_reference.rs:34:12 | 34 | as_ptr(&mut 42); | ^^^^^^^ error: The function/method `takes_an_immutable_reference` doesn't need a mutable reference --> $DIR/mut_reference.rs:38:44 | 38 | my_struct.takes_an_immutable_reference(&mut 42); | ^^^^^^^ error: aborting due to 3 previous errors